Industry trends toward miniaturization of computer systems have resulted in a requirement to fit more components into reduced enclosure volumes. One area that has been significantly space constrained relates to Peripheral Component Interconnect (PCI) slots. This is especially a concern for 1 U and 2U (a U is defined herein to be a rack height unit equal to 1.75 inches) rack optimized servers, where full height PCI slots must be oriented horizontally (i.e., parallel to the system board) in order to fit within the enclosure. To support such horizontally-disposed PCI slots, the PCI connectors may be placed on a riser board that plugs vertically into a PCI connector on the system board, thereby effectively cantilevering the PCI printed circuit boards or cards from the horizontally-disposed PCI connectors. To then support the cantilevered PCI cards, that extend horizontally from the riser board, a support structure is typically required to prevent the PCI cards from being damaged during installation and removal, and also when the system is shipped pre-configured. This support structure, or “cage”, solution (that encompasses multiple PCI adapters, the riser board and the support structure) is sufficiently heavy so that the cage typically need be mechanically retained in order to keep the riser board properly connected to the system board. PCI style connectors are fairly long (approximately 123 mm), and this length can make it difficult to ensure that both ends of the riser board are inserted sufficiently to maintain proper communication between the riser and system boards. As can be appreciated, it is imperative that the riser board be securely retained at both ends to prevent the formation of an open or intermittent contact or contacts to the system board PCI connector.
U.S. Published Patent App. No. 20040085728 A1 discloses an enclosure containing a card cage in which contact between electronic cards and card cage is accomplished by providing compression retainers. In one embodiment, electronic cards are removed by releasing a repeater retainer.
U.S. Pat. No. 6,865,085 B1 discloses an enclosure that includes a cylindrical body and one or more modular card cages adapted to receive one or more electronic circuit cards. The one or more modular card cages include an outer frame member in direct physical and thermal contact with an inner wall of the cylindrical body, an inner frame member, one or more support members coupled between the outer frame member and the inner frame member, and a plurality of electronic device retainers adapted to couple to the modular card cage and to hold each of the one or more electronic circuit cards in direct physical and thermal contact with one of the one or more support members. A device retainer keeps a positive pressure on an electronic card and provides consistent contact between the electronic card and modular card cage. An electronic card is removed by releasing the device retainer.
U.S. Pat. No. RE36695 E discloses a captive latch mechanism for use with an expansion card cage in a personal computer. The retainer further includes an intermediate section extending between the first end and the second end. The intermediate section includes a locking notch immediately adjacent the second end that is configured to releasably engage a wall adjacent the retainer aperture to thereby releasably lock the card guide retaining device in an engaged position.
U.S. Pat. No. 5,319,524 A discloses a card cage with parallel slots for circuit boards carrying retainer clips having edge fasteners for detachably connecting the clip to the circuit board, and at least one cage fastener for releasably connecting the clip to the card cage to hold the circuit board in place. Finger grips lift pivotable clasps to release retainer clips from the card cage.
U.S. Pat. No. 4,435,029 A discloses a straight locking handle that is provided for mounting a circuit card module to a card cage or rack. The module is released from the cage by pulling the handle to flex and bow the latter to a release position for disengaging the cage to allow removal of the module. Upon re-insertion, the handle is pushed flat against the front edge of the module by the operator such that the operator need not push against the circuit card module edge. After insertion, the handle is translated downwardly to a locking position engaging the cage to prevent removal of the module.